The core body temperature of a mammal, especially human, is one of the so-called vital signs that provides a strong indication of the health or medical condition of the mammal. Consequently, accurately assessing the core body temperature, frequently noting the core body temperature, and observing trends in the core body temperature are extremely important criteria in evaluating the medical condition of a mammal and in evaluating whether medical treatments are working desirably or should be implemented.
Traditional thermometers include those materials, both liquid or solid, that expand or otherwise change their physical conformation when heated. Examples include mercury and ethanol based thermometers. Such traditional thermometers usually require long equilibration times which require them to be disposed adjacent to or within orifices of a mammal for long times in order to gain a roughly accurate indication of the core body temperature.
Another disadvantage of traditional thermometers is that their use often causes discomfort to a patient or disrupts a patient's sleep.
It has been known that the body of a mammal radiates infrared radiation, which is generally associated with “heat” being radiated from the body, and which in turn is generally related to the core body temperature of the mammal. Infrared thermometers capable of sensing the infrared (“IR”) radiation emitted near the skin or other external surface of a mammal have been utilized to provide a temperature that correlates with the level or amount of IR radiation sensed. Such thermometers, however, are often inaccurate because the level of IR radiation from such a surface may be affected by sources other than the core body temperature, such as the temperature of the air in the vicinity of the surface and the presence of perspiration on the surface, thereby altering the emissivity or reflectivity of the measurement site.
One particularly advantageous location to use an IR thermometer is deep into the inner ear using a so-called tympanic probe, however, the inner ear is often occluded and the ear canal is extremely tortuous, such that the probe often does not reach deep enough into the inner ear to gain an unobstructed sighting in order to obtain an accurate reading. Moreover, the use of such a probe can cause some discomfort to a patient, and often requires that a patient be turned or moved in order to use the probe.